The product of the glnF gene, which is well-separated from the structural gene (glnA) for glutamine synthetase on the chromosome, is required for synthesis of glutamine synthetase in Salmonella, as is the product of a regulatory gene, glnR, that is very close to glnA. We have established conditions for studying the synthesis of glutamine synthetase in a coupled in vitro transcription-translation system from Salmonella using DNA from lambda-glnA phages as template. We will prepare S30 fractions from wild-type, glnF minus, and glnR minus strains in order to identify and isolate the glnF and glnR products and to determine the basis of the requirements for these positive regulatory factors.